Toilet tank



FIG. 1 is a front perspective view of a preferred embodiment of a toilet tank showing our new design;

FIG. 2 is a bottom view of the toilet tank of FIG. 1;

FIG. 3 is a front view of the toilet tank of FIG. 1;

FIG. 4 is a left side view of the toilet tank of FIG. 1;

FIG. 5 is a rear view of the toilet tank of FIG. 1;

FIG. 6 is right side view of the toilet tank of FIG. 1; and,

FIG. 7 is top view of the toilet tank of FIG. 1. 

The ornamental design for a “toilet tank”, as shown. 